The only thing I want to do is to used my customize table schema of my own. I am confused whether I used the sql.conf or the perl module.

You used sql module.

Pleaseadvice which i should used.

For you - stick to altering sql.

And if i used the perl module, please tell me how should I write the connection parameters and the sql queries for connecting to the Ms Sql.

Let's not. Get a book and learn that.

And if i used the sql.conf please tell me how to used my own customized table which contain only username and password.

You had an answer how to fix Attribute and op in radcheck query. I hope that you are aware that doing it will render radcheck useless for storing any other attributes. Ivan Kalik Kalik Informatika ISP